Total Mismatch Negative Diffusion-Weighted Imaging but Extensive Perfusion Defect in Acute Stroke

Background and Purpose-The perfusion-weighted imaging (PWI)/diffusion-weighted imaging (DWI) mismatch may identify patients who benefit from thrombolysis. However, some patients exhibit a "total mismatch," ie, negative DWI but extensive PWI defect. We aimed to assess clinical and MRI data of these patients. Methods-From June 2007 to December 2008, patients with anterior circulation ischemic stroke were evaluated for a "total mismatch" profile. MRI was performed at admission and at day 1. The score was assessed at baseline and the modified Rankin scale score was assessed at day 30. Results-Among 52 patients, 3 showed a total mismatch with arterial occlusion confirmed on magnetic resonance angiography. All had fluctuating symptoms (National Institutes of Health Stroke Scale scores, 0 to 10) and received intravenous tissue plasminogen activator. Day 1 DWI disclosed minimal changes in all patients. Outcome was favorable in all patients (day 30 modified Rankin scale, 0-1). Conclusion-PWI may be helpful for treatment decisions in patients without DWI damage and fluctuating clinical course. (Stroke. 2009;40:3400-3402.)